Client Type: Main line operator Objective To complete a study of the renewal and maintenance of switches and crossings (S&C) in support of the operator’s “Decision Support Tools (DST) Programme”. The DST programme provides an analytical framework for identifying the future work requirements for renewal and maintenance of key elements of the operator’s network. Specific objectives of the Corus study were to: - Identify degradation mechanisms, rates and life-limiting components for S&C installations.
- Develop a service life algorithm for S&C installations.
- Calculate forecasts of S&C renewal requirements up to 2020, including confidence intervals and to conduct a sensitivity analysis.
- Segment the forecasts by operator zone, track utilisation and component type.
- Analyse unfiltered track quality data for S&C to assess the relevance and applicability of the aggregated 1/8th mile track quality data as a measure of the condition of S&C.
Approach Corus co-ordinated a multi-disciplined project team to conduct the study. The team comprised expertise in research and development and rail technologies and was drawn from within Corus and from research and technology company, QinetiQ. Method Key steps in the methodology adopted to achieve the study objectives were: - Hosting a one-day workshop with industry experts to distil current engineering experience of S&C renewals and maintenance and to provide a framework for further investigations.
- Selecting a random sample of S&C renewal proposal forms from all six operator zones and transferring key information from each form into a database.
- Cross-referencing the database against the operator’s assest register data to either confirm or obtain values including those for ballast age, switch age and component type.
- Calculating the age of S&C in years and cumulative traffic tonnage carried.
- Analysing S&C age – in terms both of the complete set of sample data and of data segmented by a number of variables.
- Analysing track quality data and comparing it to the aggregated 1/8th mile data for the same locations.
Deliverables The key project deliverable was an algorithm for S&C renewals. The algorithm was used to predict the backlog of full replacements due for all types of S&C and the volume of full replacements due in 2003-2020. The results from this analysis were submitted to the national rail regulator as part of the long-term financial process for the railway. Additional deliverables were: - Documented policies for S&C renewals used by each zone.
- A review of S&C renewal proposal processes used by each zone, including the S&C appraisal documentation.
- Analysis of reasons for S&C renewals.
- Predicted average S&C service lives for each zone/stewardship category/track category.
- Variation of service life by maximum line speed/bearer type/switch type.
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